Vehicle occupant protection systems that have an actuatable protection device are known in the art. The actuatable protection device of such a system is actuated upon the occurrence of a condition for which a vehicle occupant is to be protected. An example of a condition for which a vehicle occupant is to be protected is a vehicle collision.
One type of actuatable protection system includes an air bag module mounted within a vehicle such that an air bag of the module is inflatable within an occupant compartment of the vehicle. The air bag is inflated upon the occurrence of a condition, such as a vehicle collision. Another type of actuatable protection system has a seat belt extendable across a vehicle occupant and includes an actuatable device, such as a pretensioner, to move at least a portion of the seat belt relative to the occupant. The pretensioner removes slack from the seat belt to limit occupant movement, and is actuated upon the occurrence of a condition, such as a vehicle collision.
An actuatable occupant protection system includes one or more sensors for sensing one or more parameters that are indicative of a condition for which the vehicle occupant is to be protected. For example, one sensor is a collision sensor that provides a signal indicative of a vehicle collision condition. The one or more sensors provide signals to a controller. The controller evaluates the signal(s) and determines whether to actuate the associated protection device.
One type of actuatable protection system has one or more adjustable aspects that are adjusted to change the actuation (i.e., deployment) of the protection device. For example, in a system that includes an air bag, the deployment profile of the air bag is adjustable. The adjustable aspects regarding the deployment profile of the air bag may include adjustment of a timing sequence for inflation, adjustment of pressure within the air bag during inflation and upon completion of inflation, and adjustment of air bag position with respect to the occupant.
To make determinations regarding adjustment, one or more characteristics of an occupant are sensed or are derived from occupant sensory information. Examples of occupant characteristics include: size of the occupant, weight of the occupant, position of the occupant, and distance between the occupant and a surface of a vehicle component (e.g., an air bag module).
A number of occupant imaging devices have been developed to provide sensory information regarding a vehicle occupant. In particular, an imaging device has been developed that projects structured (e.g., provided in a pattern) light onto object(s), such as the occupant and a vehicle seat, and that collects an image of the object(s) illuminated with the structured light. Determinations are made regarding detected changes (e.g., warping) of the light by features of the object(s) that the light overlays. In turn, information is deduced and used to determine occupant presence, position, range/distance, and even three-dimensional contour shape.
In addition, a device has been developed that analyzes pixel coordinates within an image of an object to determine the angular position of the imaged object within a field of view of an imager. Still further, a device has been developed that uses an imager to make a determination of major movement of an object, such as an occupant, moving across a field of view of the imager. Specifically, the imager is located such that movement of the object is transverse to a major viewing access of the imager.
A major drawback of such known devices includes a washing-out effect on structured light that is overlaid upon an object already illuminated by overly bright ambient lighting conditions. Examples of such overly bright ambient light conditions may be due to sunlight shining into a vehicle interior. One possible solution for dealing with overly bright ambient lighting conditions is to provide the structured light at a very high intensity. However, provision of very high intensity structured light typically results in undesirable high dollar costs for the necessary equipment. Another alternative is just to accept the loss of performance during such overly bright ambient lighting conditions.
Still further, other drawbacks of the known devices can produce effects that degrade performance. In one example, a correlation between range to an occupant is complicated by parallax effects as the occupant moves toward or away from the imager.